Nonlinear impact analysis of fully backed composite sandwich structures

Impact analysis of fully backed composite sandwich plates is presented, and a shear deformable model of face sheet laminates on a two-parameter elastic foundation is developed, in which the nonlinear contact law is included. The core in the sandwich is modeled as a two-parameter elastic foundation with nonlinear decay of displacement through the thickness. Hertz contact law is adopted to simulate the nonlinear impact response of the face sheet laminates. The proposed model is compared with a solution for simply supported laminated plates, and with experimental and numerical results of fully backed composite sandwich plates. The effects of core stiffness (elastic foundation), transverse stiffness of face sheet laminate, contact stiffness, and tip shape of the projectile on the impact response are investigated. It indicates that the analytical model developed can be used as a versatile and accurate tool to study the nonlinear impact response of composite sandwich structures.